Is that a pore-tightening sheet mask on your face, or are you just here to haunt my nightmares?

Chances are high that you’ve seen your favorite trendsetters posing for selfies in sheet masks, those ill-fitting, serum-soaked masks that look a little bit like a prop from “Silence of the Lambs.” You might not have a private plane like Lady Gaga, but you can take comfort in the fact that you both look like serial killers in repose when you’re enjoying the benefits of a face mask coated with snail goo and other mysterious serums.

Her sheet masks are probably made from silk spun from pampered silkworms that dine on nothing but organic mulberry leaves, and yours are from a storefront in Chinatown, but you’ll both wake up from your respective cat naps with dewy, delectable skin!

The treatments are simple, one-use cotton masks that come pre-soaked in luxurious-feeling serums that promise everything from bouncy, brighter skin to tighter pores. The serums boast a wide range of ingredients, from everyday ingredients like aloe vera and seaweed to fancier fixings like snail mucin, swiftlet nest extract, and bee venom. Some are even printed with animal faces, so you can really get in touch with your inner panda while you chill. No, really, you should definitely upload that Friday night selfie to Tinder! Wild.

You may be wondering if the masks are worth the hype, or if the best result you’re getting is a really memorable Snapchat. NYC dermatologist Dr. Dendy Engelman wonders the same thing. After all, it’s easy to get obsessed once you start reading the Asian Beauty subreddit or beauty blogs like Fifty Shades of Snail, Snow White and the Asian Pear and The Wanderlust Project, just to name a few, and sheet masks are a gateway drug. (Trust us: Before you know it, you’ll be slathering yourself with toner, essences, chemical exfoliants and serums without a second thought.)

“As a dermatologist, I always want head-to-head, placebo-controlled clinical trials that are double-blinded and tons of based-in-science studies before I’m going to make a claim to the effectiveness of a product, but of course in some of these, we’re never going to get that,” Engelman said.

The mask itself creates an “occlusive barrier,” which means it physically seals in the active serums underneath; theoretically, this helps the product work more effectively. But, as Engelman pointed out, it will be a while before anyone really cares to invest the time and money in doing the sort of rigorous testing needed to prove those claims.

Smoothing on a sheet mask, kicking back with your DVR for 20 minutes, and then tossing the mask in the trash feels decadent, but most of these masks aren’t a splurge if you know where to look and what to look for; the most expensive sheet masks currently available on the popular site Memebox are the Miss Flower & Mr Honey Mask Sheet, which are $21 for five sheets. Even Sephora and Urban Outfitters are getting into the sheet mask game, offering fan faves like Dr. Jart+, Tony Moly, and The Face Shop, as well as an in-house brand at Sephora.

Some more high-end masks are made from silk or hydrogel, but if you’d like to try a mask, you’re usually still looking at a treat that’s going to run you under $10 — sometimes way under, if you know where to shop.

Sephora and Urban Outfitters are good for impulse buys, but that’s not where you’re going to clean up, especially if you want to try a bunch of different types of masks. South Korea created and made these babies famous, but there are all sorts of Asian beauty masks on offer, from Hada Labo Tokyo to Taiwan’s My Beauty Diary, and most of them are much more reasonably priced. The diehard sheet maskers whom you see on Instagram doing, say, seven-day mask challenges are probably not the same people shelling out $79 for a four-pack of Estee Lauder PowerFoil masks. If you incorporate masks into your weekly beauty routine and stick to it, you’ll likely get more out of it, and that’s hard to do with a splurgey $17 SK-II mask.

“I think [sheet masks] work well, and certainly people like them, so that, I think, is always a benefit,” Engleman said. “If people are going to do something that’s good for your skin and they’re going to be compliant with it, then that’s always a win-win.”

As for those highfalutin’ masks by SK-II, Estee Lauder, Shiseido and the like, Engelman said they’re not particularly worth the cost.

“I cannot believe people are paying these prices for something that’s something that probably [could be] achieved by just doing additional levels of moisturization,” she said.

Until there’s some way to scientifically prove the efficacy of sheet masks over other treatments, it’s difficult for a doctor to fully lend them her support. At the lower end of the price point spectrum, sheet masks probably can’t hurt, but if you’re splurging on them, you might be better served using that money on other skincare products.

“If they work, they’re worth the investment, but I want you to save that money elsewhere. You know, don’t buy a $25 sheet mask, buy a $2 one and then save that incremental to go towards a really potent serum or something,” Engelman advised.

The good doctor’s patients also report glowing results from the masks, though not necessarily for the skincare benefits. If you fly long distances frequently, there’s a side perk. “One girl said she loves to do it pretty early in the flight so the person next to her won’t talk to her,” she said. Now we just need someone to try it on their morning subway commute and see if it works.